Search around discussions on Houzz and Pinterest. There are so many good ideas. I think a helper way than restraining walls is to change color of walls. Maybe a grey? We had similar problem with a creamy color against a walnut floor. We reprinted edge comb grey by BM and total transformation. Also take up carpet and add wainscoting on wall up stair well would make fm huge difference. Search those ideas. Nice space w tons of potential. Add a couple of chairs and side table maybe.